Flexible tray ice maker mechanism



June 7, 1966 c. E. DE TURK 3,254,505

FLEXIBLE TRAY ICE MAKER MECHANISM Filed Sept. 27, 1960 42 42 IIIINVENTOR. C/ILV/A/ 1.. Di 701W! x; OVWW United States Patent 3,254,505FLEXIBLE TRAY ICE MAKER MECHANISM Calvin E. De Turk, Cranbury, N.J.,assignor, by mesne assignments, to Philco Corporation, Philadelphia,Pa., a corporation of Delaware Filed Sept. 27, 1960, Ser. No. 58,769

1 1 Claim. (Cl. 62-353) This invention relates to an ice maker,particularly of the type which produces ice in a flexible tray, and hasto do with drive means for moving tray structure to perform variouscharging, freezing, and discharging operations. A tray structure of thetype contemplated herein is shown in the abandoned application of I. C.Courson, Serial No. 44,335, filed July 21, 1960, entitled Ice Maker andMethod of Using and Controlling the Same, and the apparatus disclosedand claimed herein is shown in the copending disclosure of the presentapplicant Serial No. 30,536, filed May 20, 1960, and issued October 2,1962, as Patent No. 3,056,271, entitled Ice Maker. Both of saidcopending disclosures are assigned to the assignee of this .invention.

It is an object of the invention to provide an ice maker, complete withdrive, which is compact and small, this being important since the trayand drive unit is desirably installed in a domestic refrigerator and thespace provided by and in such a refrigerator is valuable. It is alsodesired to construct the mechanism so that it can produce largequantities of ice, and it is further required that the device be able tooperate with a minimum of service and repair, particularly when it isinstalled in a household appliance. Still further, the drive mechanismmust op perate at subfreezing temperatures, without lubricants as usedin conventional drives; the lubricant would-be likely at the requiredsubfreezing temperatures to become viscous or solid.

Additional, important requirements have to do with certain successivemovements of the tray. It is desired that the mechanism be able, in afirst operating phase, to overturn a normally upwardly facing trayand-to cause loosening of the ice therein. During this phase it isnecessary, for proper loosening of the ice, to apply a forcible flexingmotion to the tray, which motion must occur between precise positions ofthe tray and must be relatively slow when the drive is small and compactas desired Subsequently, however, the drive mechanism should return thetray rapidly, and again with accuracy, to a position where refilling ofthe tray with water can be started. Speed is desired since on the onehand the refilling is an operation which again consumes a certain amountof time and since on the other hand the complete operating cycle shouldbe as short as possible in order to'seoure maximum production of ice. Insome instances it is also desired to provide a vibratory or jarringmotion, at the point where the tray is returned to its normal position,it being possible by such motion to return the tray to its normal shape.

It is accordingly a specific object to provide for successive slow andrapid motions of the ice tray and of its compact, unlubricated drivingsystem and to limit both motions exactly as to their points of start andfinish. Another related object is to provide for controlled, successiveslow motions and rapid vibratory motions of the tray.

I have found it possible to achieve these several objects with the aidof a system using a remarkably simple es-' capement. In a preferred formthis escapement comprises a rotary driving element and a rotary drivenelement, one of said elements being rigidly secured to a motor shaft andthe other, in slightly eccentric position, to the tray, and both beinginstalled in the refrigerated atmosphere and adapted to operatesubstantially without libricating oil. The operation of the escapementunit canbriefly be characterized by saying that the driving elementimparts a portion of one turn and up to a predetermined point ofescapement of the driven element from the driving element, where aresilient element provides for rapid return of the tray to the normal orzero position, advantageously with vibration of the tray, while the slowmotion of the driving element continues, effecting a refill controlaction and ultimately resetting the driving element at the zero point.These and related features will best be explained in the followingdescription of an embodiment of the invention.

In the attached drawing FIGURE 1 is a perspective view of an ice makerincorporating the automatic drive and escapement mechanism of thisinvention. FIGURE 2 is a fragmentary, sectional view, taken generallyalong line 2-2 in FIGURE 1 and indicating different positions andmotions of driving and driven elements of the escapement device. FIGURE3 is a schematic representation of electrical circuits desirably used inthe operation of' by well known refrigerating apparatus, not shown.Thereafter the tray, with the ice frozen therein 'and adhering to thewalls of the tray, is overturned by means comprising output shaft 11 ofmotor M and escapement mechanism 12 driven by said shaft. This mechanismis provided in accordance with the invention in order to obtain areversible two-speed rotation of the tray from the unidirectionalsingle-speed rotation of the motor shaft.

Said unidirectional rotation is indicated by an arrow R which isdirected counterclockwise as seen in FIGURE 2. This rotation of themotor shaft is initially applied by the escapement mechanism to oneend'of the tray, whereby it overturns the tray, engages the opposite endof the tray with a stop device 13, FIGURE 1, and then causes therotation of the driven end of the tray to continue,

' thereby flexing and twisting the tray and causing the ice to breakloose and to slide out of the overturned and flexed tray.

When this has been done, the escapement mechanism disconnects the trayfrom the motor shaft, as will be described presently. At this point itis to be noted that a spring 14 then returns the disconnected tray to astop device 15, advantageously in a rapid snap action or vibratoryimpact, thereby returning the tray to its normal filling and freezingposition and to its normal unfiexed form and making it possible to beginproper refilling of the tray at once upon the harvesting of the ice.Meanwhile the motor shaft continues its unidirectional, relative slowrotation, incident to which it controls the required opening and closingof automatic fill valves for the ice tray and, as a final phase of eachoperating cycle, elfects resetting of the drive shaft in zero position,as will be described hereinafter.

The preferred form of the escapement, provided in accordance with theinvention and best shown in FIGURES 2 and 4, includes a rigid finger 16radially extending from motor shaft 11, with a rigid finger tip 17constructed and arranged in form of a small plate member secured to thefree end of the finger and lying in a plane radial of shaft 11.Similarly a finger tip 18 is provided on a finger 19,

the latter finger tip lying in a plane radial to a shaft 20 The soarranged finger tips 17, 18 can easily be adjusted so as to be inengagement one with the other over a predetermined, angular part of acomplete rotation of the tray-supporting shaft 20, and only over suchpart (FIGURE 2). For this purpose the center of tray shaft 20 lies on asmall circle C about the center of motor shaft 11, at a point more than90 degrees from the normal or zero point of both fingers, to insureoverturning of the tray. The center of shaft 20 also lies substantiallyless than 360 degrees from said point (always in the direction of motorrotation R), to provide for valve control action as will be describedhereinafter.

Accordingly, when the directly driven end of the tray reaches a point 24of said rotation R (FIGURE 1), such as to obtain the desired degree offlexing beyond stop 13, the relative positions of the two fingers,FIGURE 2, are such that the engagement of the two finger tips is lost,as is shown in this latter figure in full lines.

Thereupon the tray finger tip 18 is free to escape from its formerengagement with the motor-driven finger tip 17, the tray finger 19 beingurged to such escape by the spring force S supplied by spring 14. Thespring-actuated finger 19 and the tray then return to their normalposition by rapid, snap acting return rotation, thereby bringing oneedge portion of the tray into contact with stop 15 (FIGURE 1) and thuscausing vibration or jarring I of the tray, (FIGURE 2), as more fullydescribed in said Courson application. Meanwhile the motor shaft 11 andmotor finger 16 continue their relatively slow rotation R.

The complete operation of the new ice maker mechanism can now bedescribed as follows:

Subfreezing temperatures are maintained around the ice maker but duringthe freezing of water in tray the temperature of the tray substantiallyremains at the freezing point of water. A similar temperature thenexists in a bellows 25, FIGURE 3, which senses the temperature of thetray by a suitable contacting mechanism 26, FIGURE 1, more fullydescribed in said Courson application. When the freezing of ice has beencompleted, the temperature falls to a lower level in the tray, andcorrespondingly in bellows 25, causing contraction of this bellows andclosing of a switch 27, FIGURE 3. This now starts motor M, therebyslowly rotating the motor shaft 11 and motor finger 16. The slow,unidirectional rotation of this finger forcibly turns finger 19 andtwists the ice-filled tray, causing the ice to break loose and slide outof the tray, as already described. This is followed by the escapementaction which has also been mentioned.

In this escapement action spring 14, FIGURE 1, effects rapid, clockwisereturn rotation and unflexing of the now empty tray. For this purposethe spring, which desirably surrounds tray shaft 20, has one end 28secured to a stationary bracket 29 on support structure 23, while havingits other end 30 engaging a bracket 31 secured to one end of the tray.(It may be noted that a generally similar bracket 32 is providedadjacent the stationary end 28 of the spring; this other bracket isloose on tray shaft 20 and serves only as a guiding element.) Thespringengaged bracket 31 is fast not only on the tray but also on saidshaft and thereby rigid with tray finger 19, the fastening of the trayshaft to this spring-engaged bracket being effected by a pin 33. Thetray is secured to the two brackets by fasteners 34. By means of thesesimple arrangements it is possible for the unidirectionally rotatingmotor finger to turn a first or power end of the tray, including bracket31, to gradually and forcibly flex the tray counterclockwise (R), andwind up the spring (see part F of arrow R in FIGURE 2, which suggeststhe gradual increase ofthe spring force) until the predeterminedposition 24 is reached, Whereafter the spring can move the tray and trayfinger rapidly and clockwise (S).

During and after the split second return motion of the tray therelatively slower unidirectional rotation R of 4: motor shaft 11 iscontinued by motor M and it will now be noted that said shaft operatescontrol means, shown in FIGURE 3 as a pair of earns 35, 36. At anysuitable point 42" of rotation R of the motor shaft (FIGURE 2),corresponding to some suitable time after the start of such rotation,the first cam 35 by means of follower 37 (FIG- URE 3) closes a switch 38which from then on keeps motor M energized regardless of the position ofthermostatic switch 27. (This latter switch then opens, as theaforementioned follower 37 closes a further switch 39 energizing a smallheater 40 which returns thermostat bellows 25 to the normal expandedposition thereof.)

In due course thereafter, the continuing unidirectional rotation ofmotor shaft 11, at point 42" (FIGURE 2), establishes a position whereinthe second cam 36 (FIG- URE 3) closes a switch 41, opening a valve V ina tray refilling system 42. The valve opening operation 42' (FIGURE 2)is now caused by this latter timing cam to take place, during a portionof the motor cycle in which the escapement of finger 19 from finger 16has taken place, so that the tray by then has safely returned to itsnormal position for filling.

Water now enters one of the series of tray compartments 51 to 57 (FIGURE1), overflowing by way of suitable notches 58 in the partitions 59dividing these compartments. Ultimately (FIGURE 3) the motor shaft 11turns cam 36 to a position wherein filling switch 41 opens and fillvalve V closes, and shortly thereafter the other cam 35 by follower 37reopens switches 38, 39, thereby replacing the control structure in itsoriginal position so long as thermostatic switch 27 remains open.

It will now be appreciated that the new drive and escapement,characterized by the two simple fingers 16, 19, causes the tray to bemoved slowly and forcefully in counterclockwise direction R, F foroverturning, twisting, and harvesting, whereafter it causes the trayrapidly-resiliently to return to its normal position while one of thefingers continues to complete a slow rotation for purposes of fill-valvecontrol and resetting. It will also be seen that the start and endpoints of these slow and fast motions can readily be controlled in aprecise way, that nevertheless no complex, lubricated device isrequired, and that the mechanism can readily operate at a subfreezingtemperature.

While only one embodiment of the invention has been described, it shouldbe understood that the details thereof are not to be construed aslimitative of the invention, except insofar as is consistent with thescope of the following claim.

I claim:

Escapement apparatus for controlling an ice maker of the type wherein aflexible ice tray is subjected to consecutive filling, overturning,flexing, unfiexing, and returning operations, comprising:

an approximately horizontal tray shaft for the support of said tray,subject to pivoting motions throughout said operations;

a motor shaft having an end portion opposite an end portion of said trayshaft and generally aligned therewith but slightly eccentric thereof;

a pair of finger means, one secured to each of said end portions, saidfinger means extending approximately radially of said respective shafts,one generally opposite the other, and being capable of engagement onewith the other throughout a major portion of said operations and, bymeans including the eccentricity of the shafts, capable of escapementfrom one another during the remaining portion of said operations; and

means for driving said motor shaft uni-directionally through a singlerotation for thereby initially providing said engagement between saidfinger means to overturn the ice tray and then to flex it, and for thenproviding said escapement to allow the returning operation of th icetray while also allowing continuation and ultimate completion of saidsingle rotation of the motor shaft.

References Cited by the Examiner UNITED STATES PATENTS 8/1956 Sampson62267 Galin 623'70 Schweller Q. 62369 Galin 62370 Nelson 62370 ROBERT A.OLEARY, Primary Examiner.

EDWARD J. MICHAEL, Examiner.

G. A. EPPNER, Assistant Examiner;

